improve integration tests verbose mode (#261)
improve integration tests verbose mode (#261)

Motivation:

Previously, the integration test's verbose mode would only shows the
output after the test has run, but a live view is better.

Modifications:

Made the integration test's verbose output live.

Result:

Easier to debug the integration tests.
apple/swift-nio,apple/swift-nio,apple/swift-nio,apple/swift-nio,apple/swift-nio